const _quickSort = array => {
  let target = array[0]
  let left = []
  let right = []
  for(let i=0;i<array.length;i++){
    if(array[i]<target){
      left.push(array[i])
    }else{
      right.push(array[i])
    }
  }
  left = _quickSort(left)
  right = _quickSort(right)
  left.push(target)
  return left.concat(right)
}